


Square Peg

by kisahawklin



Series: The Three Body Problem [6]
Category: Supernatural
Genre: Dildos, Dirty Talk, M/M, Multi, Plot What Plot/Porn Without Plot
Language: English
Status: Completed
Published: 2015-02-05
Updated: 2015-02-05
Packaged: 2018-03-10 14:09:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,963
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3293246
Author URL: https://archiveofourown.org/users/kisahawklin/pseuds/kisahawklin
Summary: <blockquote class="userstuff">
              <p>Cas recruiting Sam to hold Dean down while he fucks him slow with a huge dildo.</p>
            </blockquote>





	Square Peg

**Author's Note:**

  * For [Mirob (DestielOfDoom)](https://archiveofourown.org/users/DestielOfDoom/gifts).



> So Three Body Problem was really just an excuse for me to write Wincestiel porn snippets forever. Mirob suggested this one first, so this one came first. I'm sure there are many more of these to come in the future.

Sam doesn't even know what for, but when Cas gives him the little eyebrow-lift-and-nod, he follows right along.

They do this; usually there's a ringleader and then the one they can rope into playing a trick on the other one. Sometimes it's specific – like the time Dean got Cas to shortsheet the bed because he knows how much Sam hates it – and sometimes it's general – like when Cas got Sam to help him build a snowman because he knew if two of them were playing in the snow, the third would make their way out and they could have a proper snowball fight.

Sam has no idea which one this is, what Cas's plan is, but Cas is never mean-spirited, so he goes along with it. 

Cas leads him into the kitchen, where Dean is stirring a huge stockpot full of soup. 

"Mmm," Sam says, putting his face into the steam and taking a whiff. "Chili."

Cas comes up behind Dean and puts his arms around Dean's waist, resting his chin on Dean's shoulder. Dean just relaxes back against Cas, holding one hand out to Sam to reel him in. 

"Should be ready for dinner," Dean says. "Just needs to simmer for a while."

"Good," Cas says, turning Dean around for a kiss. "We have time for some sex, then."

Sam laughs. They have yet to be able to teach Cas to use euphemisms for sex. He knows them all and understands when Sam or Dean uses one, but never uses any himself. It's one of his most endearing traits.

"What did you have in mind?" Dean asks, glancing back at the stockpot.

They have scenarios that are weeks in the planning and use every ounce of Sam's not-inconsiderable engineering skills. They have scenarios that come up in the heat of the moment that Sam is pretty sure they will never act out, unless they keep going in the heat of the moment. There's plenty of "whatever happens, happens" that goes on, too, one of them crawling onto another's lap and kissing them stupid while the third figures out how they're all going to get to orgasms. Sam likes those times, especially when it's Dean crawling into his lap and Cas giving the orders.

This seems to be a middle ground sort of tryst, something Cas believes won't take more than a couple of hours. He takes Dean's chin in hand and gently makes him face forward, looking into Cas's eyes. "We'll be done by dinner," he says, planting a kiss on the side of Dean's mouth and grabbing his free hand, leading them all to the bedroom, like a chain of kindergarteners crossing the street. 

They learned within the first month that it's easiest if they all just strip themselves. Dean and Sam are both trained at stripping other people efficiently, but it's not like it adds anything to the allure, and none of them really care that much about stripping, as much as Dean likes to protest otherwise. So they pull their clothes off in a hurry, Dean taking the longest because he always wears three layers, and Sam will never understand why.

By the time Dean's done shucking his jeans, Cas has pulled out a gigantic bottle of lube. Dean loves to be penetrated (not that he would _ever_ say that out loud) and Cas loves to drive him crazy with it. He knows some secret mojo about the prostate, Sam's pretty sure. Sam doesn't usually have much to do when Cas is in this sort of mood, but he likes to watch. Sometimes Dean will whine enough that Cas will let Sam fuck his mouth just to shut him up – and that will never get old, as far as Sam is concerned, because the look of utter bliss on his brother's face as Sam shoves his cock in Dean's mouth is one of Sam's favorite things.

Today, though, Cas gives him another raised eyebrow and a nod, which, in this situation, is a signal for Sam to wrangle Dean into holding still for Cas to do whatever he wants. 

Dean is good with orders but bad with patience. If Cas isn't telling him what to do, he goes crazy trying to figure out what he should be doing. Sam's job, in times like these, is to give Dean something to concentrate on.

Cas orders Dean onto the bed on all fours, and Dean scrambles to obey. He's crazily enthusiastic, which is annoyingly adorable. Sam expected him to rebel against the orders, maybe gun for a little punishment – spanking, probably – but no, Dean just really likes doing what he's told. 

Once he's on the bed, Cas nods at Sam, and Sam puts one hand between Dean's shoulder blades, pressing down firmly, his other hand pushing Dean's arms outward, stretched out in front of him, his head dropping to rest on the bed. For whatever reason, Dean's hips tilt back whenever Sam puts him in this position, and Cas nods approvingly. 

"Hold still, Dean," Cas says, and Sam feels a fine tremor go down Dean's spine. It's one of Cas's toughest orders for Dean – he is always in motion. Even standing still he feels like a tornado caught in a jar. 

"Sam," Cas says, and Sam takes his cue. He's to hold Dean down while Cas does whatever it is he's thought up for the afternoon. Sam shifts to put his hands on Dean's shoulders, squeezing once reassuringly and then sliding his hands down Dean's arms until their hands are linked.

Sam's pretty sure if he and Dean hadn't been raised the way they were, Dean would be kinky as hell, and _really_ into bondage. As it is, though, it hits too close to home, so Dean never lets them tie him up or restrict him in any way that he doesn't feel like he could get out of if he needed to. 

He likes having something to hold onto, though, so when Sam links their hands, Dean holds on for dear life, grounding himself and breathing deeply in anticipation of whatever Cas has in store.

When Sam looks back up at Cas to signal Dean's readiness, he's standing there with the biggest dildo Sam has ever seen. It's not like he's seen all that many, but he's fairly certain that one that's as thick as his forearm and a foot and a half long has got to be in the running for world's largest.

Sam swallows his surprise; the last thing he needs is for Dean to get tense before Cas tries to shove that monster in him. Cas squirts some lube into his hands and starts in his usual way. Sam can't see his hands from this position, but judging by Dean's low moan, Cas's fondled his balls and started stroking his perineum.

Sam's prepped Dean before, under Cas's watchful eye, so he knows all the tricks to making Dean desperate to be fucked, exactly as out of control as the first time. He knows, but he wishes he could watch Cas's handiwork all the same. Dean's got his face down on the bed, so Sam has to read his pleasure in the way his muscles move under his skin instead.

Dean's breathing goes erratic and he squirms, minute shifts of his hips as he tries to get something Cas isn't ready to give him yet. His fingers squeeze and release Sam's hands, over and over, and he moans constantly, breathy and then full-throated, vocal representations of the kneading he's doing with his fingers. 

Sam can tell what Cas is doing by Dean's reactions; how many fingers are spreading Dean open, how consistently Cas is hitting the bundles of nerves that overload Dean's circuits and leaving him a panting mess, whining for more in the back of his throat because his words have deserted him. 

Even so, Sam can hear the intonation of his name in the sounds; there's a rhythm, a pitch to it that screams _Sammy_ even if Dean can't quite say the word. 

Things ease off just a little; Dean's non-verbal sounds calm down to harsh breathing, his forehead pressed hard into the coverlet, and Sam can see Cas lining up the dildo, the first gentle nudges making Dean moan. It doesn't take long for it to shift into something else though, soft _nnn_ sounds that Sam might take for Dean backing down if he didn't know Dean never backs down. 

"Shhhhhhh, it's okay, Dean. Relax," Cas says as he continues to pry Dean open. Sam can feel Dean resisting, though, can see it in the set of his shoulders and the sweat breaking out on his back. So he gets down on his knees, shifting both of Dean's hands into just one of his, and brings his face in toward Dean's. He nuzzles at Dean's temple with his nose, kissing his cheekbone and rubbing his lips along it to Dean's ear. 

"Over here, Dean," Sam whispers, his words barely more than breath. "Show me what you've got."

Dean turns his face to Sam, and Sam can see the effort etched into his features; he's trying to relax, but it's not working. The muscles of his back clench up and relax as Dean tries his best to do what Cas needs so he can get the dildo further in. 

Sam decides to go another way. He hasn't tried this before, none of them really talk much except Cas when he's giving orders, but he has a good feeling about this. Dean's just so easily suggestible.

"You know what this is for, don't you Dean?" Sam asks, bring his face in close to Dean's, whispering right next to Dean's ear. He can't look at his brother while he's talking or he'll die of embarrassment.

"Nnn," Dean says, turning his face toward Sam's like he can't help it. 

Sam presses their cheeks together. "He's stretching you so you can take both of us."

Dean exhales hard at that, shuddering and pressing himself down into the bed. Sam looks up at Cas and sees him smile, nodding slightly. "Good, Dean."

Sam's been thinking about this for a long time. He's done extensive research on the easiest and most comfortable way to get two cocks into one person, and he knows exactly how they're going to do it. 

"I'm going to fuck you slow," Sam says, listening to Dean's breathing turn ragged, "and spread you open so Cas can slide right in alongside me, both of us fucking you, just how you like it."

Cas is a tough customer, sometimes. When he's running the show like this, he doesn't usually get overly-aroused – sometimes he doesn't even get hard. They've spent enough time together that it doesn't bother Sam anymore; as long as they take the time to doubleteam Cas later to make up for it, he doesn't mind if Cas gets a more cerebral pleasure out of watching him and Dean.

Cas is aroused now, though, blinking at Sam like he's some new brand of supernatural creature that's been hiding away in their bed. He's stopped moving the dildo into Dean, but it doesn't matter. Dean is squirming backward, his body automatically reaching for what Sam's talking about. Sam laughs, low and dirty, and whispers, "I think maybe we'll see if we can't get you to come just from our cocks in you, taking turns sliding in deep."

"Sammy," Dean whines, fine tremors running along the muscles under Sam's hands. "Please."

They all have different threshholds for begging; Cas only begs when he gets overloaded, wanting the release of orgasm. Dean, he almost always does it for cock. They haven't managed to make Sam beg yet, even though they've tried a dozen times each. Sam's sure they'll figure something out, but he's in no rush. They've got all the time in the world to figure each other out.

It seems that dirty talk is a hit with both Cas and Dean, though, so Sam's going to have to practice. 

"You're not ready for us yet, Dean," Sam says, meeting Cas's eyes and keeping himself from laughing when Cas finally snaps back to the here and now and takes control of the dildo again. "You have to show us you can take us both, come on, now, let's see you take this."

Dean moans, his words gone again, his body heating up under Sam's hands. He's close; he always gets feverishly hot right before he comes. They've tried to get him to come without a hand on him, but they haven't been able to yet; Sam thinks maybe it's the dirty talk they've been missing – putting pictures into Dean's brain while they're taking him apart. "Just like that, Dean, show me how deep I can fuck you, how you're going to let Cas push right inside you too, so tight, so full…"

And that's when Dean hitches, his body jerking with his orgasm, calling their names. "Cas… Sammy…" Always both of them. Sam would think it was deliberate; if it was him, it would be deliberate. But Dean's not that coherent during or after sex. He's completely on autopilot, and Sam'll never admit it, but the name thing always turns him into a big marshmallow in the inside.

They gentle Dean through the aftershocks – long this time, nearly half a minute of Dean's hitching breaths and spasming muscles. He's crying, too, tears slipping silently down the sides of his face. It happens sometimes after sex when it's really good. Sam doesn't mention it. It doesn't help with the gooshy insides, though.

Once Cas has taken out the dildo and Dean is breathing normally, Cas throws himself at Sam, knocking him backward on his ass and crawling onto his lap, both hands on Sam's face and kissing him like the universe is ending. Sam sits up, trying to get in the game; he doesn't mind Cas being all bossy, but it's better when they're pushing at each other. 

"Will you please fuck me right now?" Cas asks, hands moving from Sam's face to his cock and getting him condomed and lubed up in record time. Sam takes a second to check in with Dean, who's sprawled out on the bed, eyes heavy-lidded but still tracking everything that's going on. He flops out a hand, connecting with Cas's shoulder, and Cas leans away from Sam to rest his shoulder against Dean's palm for just a second. 

"Right _now_ , Sam," Cas says, and Sam is nodding his head crazily, absolutely on board with this, because when Cas rides one of them, it's best to let him do his thing and hold on for dear life.

Cas takes Sam's cock in hand and lowers himself onto it. Sam knows Cas is moving as fast as he can, consciously relaxing and lowering in a way Dean's still trying to learn, but it's still an eternity before Sam can concentrate on anything at all besides trying not to stroke out while Cas works himself down to sitting on Sam's pelvis. Once Sam's completely inside, Cas tenses, and Sam groans and closes his eyes. 

His hands are resting on Cas's thighs, just for somewhere to put them because Cas doesn't like them on his hips. Cas likes to be in charge when he's on top. Sam moves his hands up to Cas's waist; sometimes Cas will let him help if he gets tired or too out of control.

Cas is subdued most of the time. He's analytical and thoughtful and not usually aggressively sexual the way both Sam and Dean can be. But every once in a while, he gets absolutely animalistic, and he takes whatever the hell he wants. It's hotter than anything Sam's ever seen, and there's nothing to do but go along for the ride.

"Fuck, Cas," Dean says, his voice even rougher than usual, "show that kid who's boss."

Sam would throw an insult Dean's way, but he's already out of breath just trying to keep up with Cas, and he decides if he wants to be able to walk tomorrow, he should probably get Cas to hurry up. He slides his hands down Cas's hips and tucks one under Cas's balls, cradling his sac while pressing up on his perineum, and slicks the other with some of the lube that's all over him and circles Cas's cock. 

It breaks Cas's rhythm, which is just enough to surprise him into coming, streaks of it on Sam's chest and stomach and face. Sam was following right after Cas anyway, but Dean's fingers sliding through Cas's come on his hip are enough to make him see stars. He falls back onto the floor, waiting for his heart to slow back down to normal so he can get up without worrying about a heart attack. 

"That's one filthy mouth you got on you, little brother," Dean says, and Sam just raises an eyebrow because seriously, that was _nothing_. Sam's writing goddamn epic porn poetry in his head, and he cannot wait to try it out the pair of them; hopefully when they're stuck in the Impala, hours away from the bunker with no escape and Sam can have them squirming in their seats.

"Hmm, yes," Cas says, bringing a damp towel over for Sam and taking another to clean Dean before using it to wipe himself down. "That was a surprise." 

Sam throws his towel at Cas's head, but Cas catches it, using it to clean off the dildo he'd abandoned next to Dean on the bed. Dean rolls over and catches his first glimpse of the thing. "Holy shit," he breathes, his eyes going round. "That thing was in me?"

"Took it like a champ," Sam says, twisting out of the way of Dean's flailing punch.


End file.
